Optica Technologies — fraud agreement

Respected sir/madam,
Myself Kiran kumar, got a mail for online part time job from [protected]@gmail.com in which tell about the captcha code filling, fill 10000 captcha in 10 days in which 90% should be correct and they send me one link through which one app had opened where they said to upload my photo and name along with they asked me to send my AADHAAR photo in whats app ([protected]) and i have send them. After few minutes they send me a agreement where they put my signature and photo without my permission. Now I have completed the job within 10 days and send them. Next day they sending messages continuously that 90% work is not correct, so i have to pay the penalty of rs 5000/- or they take legal action. Next day they send me a legal notice through mail from [protected]@gmail.com in which no any advocate details are there. They continuously sending the messages and it become a problem at my home as parents came to know this issue by seeing messages in my mobile. Now i found it fraud so please help me from this fraud contract.
Please help me to resolve my problem a quick action will be expected from my side.
Thanking you